A known example of a remote control system of the type defined in the opening paragraph is an audio system with a two-way remote control that uses a messaging protocol to retrieve status messages on a screen of the remote control. The messaging protocol is used to display information concerning the current values of system parameters such as the audio volume or the selected audio source. For that purpose, the remote control of the known remote control system is capable of sending a request message to the audio system. The request message comprises a code of some kind to indicate which type of information is requested. The request code is interpreted by the audio system and the proper information is transmitted back to the remote control. Status information can be sent as a predefined status code, requiring the presence of a lookup table or translation algorithm in the remote control that translates the status code into the proper status message. That message is then displayed on the display screen of the remote control. Alternatively, the status message is sent to the remote control as plain text, so that it can be displayed directly. This solution is most common in status messaging protocols, since no lookup table or translation is required on the remote control.
A disadvantage of the known system is that if the remote control can display more than one status message on a single screen, and particularly if a multi-tasking operating system is running on the remote control, it may be unclear to which status message field on the display screen a received status message pertains. Depending on how the operating system is designed, multiple status requests may be transmitted successively without awaiting the related status messages from the controlled device. Due to physical communication failures some requested status messages may not have been received by the remote control. If the operating system is multi-tasking, the status message can appear at an arbitrary time in an internal buffer while the operating system is busy with other tasks. When more than one status message field is present on the screen of the remote control, the operating system will not know in which field to put the status message that is present in the buffer.